Coin-type secondary battery, manufacturing method therefor, and apparatus for charging/discharging coin-type secondary battery

ABSTRACT

The present disclosure relates to a method for manufacturing a coin-type secondary battery. The method includes at least: bonding one or more solid electrolytes to an anode upper case; forming an anode active material layer on an anode current collector; sequentially stacking the anode current collector on which the anode active material layer is formed and the anode upper case to which the one or more solid electrolytes are bonded on an anode bottom case to obtain an anode part; sequentially stacking the anode part, a separator, a cathode current collector, and a second case including one or more openings on a first case; bonding the first case to the second case; and introducing an ion-containing solution containing sodium, lithium, magnesium, and a combination thereof from the outside of the second case into an interior thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 15/576,762 filed Nov. 24, 2017, which is a National Phaseapplication of International Application No. PCT/KR2016/005527 filed onMay 25, 2016, which claims priority of Korean Patent Application Nos.10-2015-0073108, filed on May 26, 2015 and 10-2016-0059039, filed on May13, 2016, in the Korean Intellectual Property Office. The above-listedapplications are incorporated herein by reference in their entirety.

TECHNICAL FIELD

The present invention relates to a coin-type secondary battery, a methodfor manufacturing a coin-type secondary battery, and an apparatus forcharging and discharging a coin-type secondary battery.

BACKGROUND ART

Generally, a secondary battery refers to a battery capable of beingcharged and discharged through a conversion between chemical energy andelectric energy using a material capable of electrochemically reactingwith a cathode and an anode. The secondary battery is mainly used inapplications in which a large amount of electric power storage isrequired, such as a vehicle, a ship, or the like.

A typical example of the secondary battery includes a lithium secondarybattery that generates electric energy due to a change in a chemicalpotential thereof when an ion of a metal (e.g., lithium, sodium, or thelike) is intercalated and deintercalated in a cathode and anode thereof.

The lithium secondary battery is manufactured using a material capableof reversible intercalation and deintercalation of lithium ions as anactive material of the cathode and anode thereof, and filling an organicelectrolyte or a polymer electrolyte in a space between the cathode andthe anode.

However, a limited amount of lithium is present on Earth, and lithium isgenerally obtained from a mineral, a salt lake, and the like through adifficult process. Therefore, there is a problem in that high costs andhigh energy are used for manufacturing a battery, and thus anext-generation secondary battery which allows lithium to be replacedwith another material is needed.

Such a lithium ion battery has a risk of explosion, and a lithium metaloxide (e.g., LiCoO₂, LiMn₂O₄, and the like) used as an active materialof a cathode thereof has a high price, and thus there are problems inthat high costs are required to implement a large scale energy storagesystem (ESS), and environmental problems may be caused during disposalof waste batteries. Further, when an installation site is selected, asocial issue such as objection of residents and the like is highlylikely to arise due to a lithium ion battery facility being mistaken fora facility such as a nuclear power plant.

To overcome these problems, it is necessary to reduce the risk ofexplosion and select materials that are eco-friendly, abundant on Earth,and are inexpensive, and thus it is necessary for a battery systemcapable of preventing a conflict with community members when aninstallation site thereof is selected to be developed, but research onsuch a battery system is insufficient.

DISCLOSURE Technical Problem

To overcome the above problems, the inventors of the present inventionpropose a coin-type secondary battery in which a solid electrolyteselectively passing a specific metal ion is applied to an anode partthereof and an ion-containing solution (e.g., seawater) includingsodium, lithium, magnesium, and a combination thereof is applied to acathode part thereof, wherein the ion-containing solution flows into thecathode part from the outside of the cathode part, and a method formanufacturing the same.

Further, the inventors of the present invention propose an apparatus foreasily charging and discharging a coin-shaped secondary battery.

Technical Solution

According to one embodiment of the present invention, there is provideda coin-type secondary battery including an anode part; a cathode part; aseparator disposed between the anode part and the cathode part; a firstcase disposed outside the anode part; and a second case disposed outsidethe cathode part and including one or more openings, wherein the firstcase and the second case are bonded to each other; the anode part, theseparator, and the cathode part are sealed by the first case and thesecond case which are bonded; the anode part includes an anode bottomcase, an anode current collector disposed on the anode bottom case, andan anode upper case to which one or more solid electrolytes are bonded;the anode upper case includes one or more openings; the one or moresolid electrolytes are disposed at the one or more openings in the anodeupper case; the cathode part includes an ion-containing solutioncontaining sodium, lithium, magnesium, and a combination thereof, and acathode current collector impregnated into the ion-containing solution;and the ion-containing solution flows into the cathode part from theoutside of the second case through the one or more openings of thesecond case.

Specifically, a description of the anode part is as follows.

The anode part may further include an adhesive disposed on each of theone or more solid electrolytes which are disposed at the one or moreopenings in the anode upper case, and configured to bond the electrolyteto the anode upper case.

More specifically, the adhesive may include one or more materialsselected from the group consisting of a silicon (Si) based material, anepoxy based material, and a combination thereof.

In the anode part, the solid electrolyte may be selected from the groupconsisting of a Na superionic conductor (NASICON), a Li superionicconductor (LISICON), an amorphous ion conductive material, a ceramic ionconductive material, and a combination thereof.

The anode part may further include an anode active material layerdisposed over the anode current collector, the anode active materiallayer may include an anode active material, and the anode activematerial may be one or more materials selected from the group consistingof a metal, a metal oxide, a metal sulfide, a metal phosphide, acarbon-based material, and a combination thereof.

The anode part may further include a liquid electrolyte.

The liquid electrolyte may include a dissociable salt and an organicsolvent.

At this point, the dissociable salt may be one or more materialsselected from the group consisting of a sodium compound, a lithiumcompound, an ammonium compound, and a combination thereof.

Further, the organic solvent may be one or more materials selected fromthe group consisting of an ether-based organic solvent, acarbonate-based organic solvent, a nitrile-based organic solvent, and acombination thereof.

Meanwhile, a description of the cathode part is as follows.

In the cathode part, the ion-containing solution may be selected fromthe group consisting of seawater, salty water, and a combinationthereof.

The cathode part may further include a catalyst electrode disposed onthe cathode current collector, and the catalyst electrode may includeone material selected from the group consisting of a metal oxide, anovel metal material, a carbon-based material, a perovskite-basedmaterial, and a combination thereof.

According to another embodiment of the present invention, there isprovided a method for manufacturing a coin-type secondary battery, themethod including bonding one or more solid electrolytes to an anodeupper case; forming an anode active material layer on an anode currentcollector; sequentially stacking the anode current collector and theanode upper case to which the one or more solid electrolytes are bondedon an anode bottom case to obtain an anode part; sequentially stackingthe anode part, a separator, a cathode current collector, and a secondcase including one or more openings on a first case; bonding the firstcase to the second case; and introducing an ion-containing solutioncontaining sodium, lithium, magnesium, and a combination thereof fromthe outside of the second case into an interior thereof, wherein, in thebonding of the one or more solid electrolytes to the anode upper case,one or more openings are disposed in the anode upper case and the one ormore solid electrolytes are bonded to the one or more openings in theanode upper case; and, in the introducing of the ion-containing solutioncontaining sodium, lithium, magnesium, and a combination thereof fromthe outside of the second case into a cathode part, the ion-containingsolution flows from the outside of the second case into the cathode partthrough the one or more openings of the second case.

Specifically, the bonding of the one or more solid electrolytes to theanode upper case may include bonding the one or more solid electrolytesto the anode upper case using an adhesive.

At this point, the adhesive may include one or more materials selectedfrom the group consisting of a silicon (Si) based material, anepoxy-based material, and a combination thereof.

Each of the one or more solid electrolytes may be selected from thegroup consisting of NASICON, LISICON, an amorphous ion conductivematerial, a ceramic ion conductive material, and a combination thereof.

According to one embodiment of the present invention, there is provideda charging and discharging apparatus including a vessel filled with asolution containing water or sodium ions; a jig part installed at thevessel, having an interior in which a coin-type secondary battery ismounted, and configured to allow a cathode part of the coin-typesecondary battery to be brought into contact with the solution in thevessel; an anode terminal installed at the jig part and electricallyconnected to an anode part of the coin-type secondary battery; and acathode terminal electrically connected to the cathode part of thecoin-type secondary battery.

The jig part may include a case installed at the vessel and in which aseating part on which the coin-type secondary battery is seated isformed at a front surface of the case facing an interior of the vessel;a sealing member installed to surround an outer circumference of thecoin-type secondary battery and configured to seal between an anode partof the coin-type secondary battery and the case to block the solutionfrom flowing into the anode part in the case; and a cover member coupledto the front surface of the case, configured to tightly pressurize thesealing member, and in which a hole is formed on a front surface thereofto expose the cathode part of the coin-type secondary battery.

The case may have a structure in which a circular flange is formed alongan outer circumference of the front surface of the case, and a malescrew thread is formed on an outer circumferential surface of thecircular flange so that the case is screw-coupled to a female screwthread of a hole formed on a side surface of the vessel to be detachablyinstalled thereat.

The case may have a structure in which a ring member configured to sealis installed at the circular flange to seal between the case and thevessel.

The cover member may have a structure in which a male screw thread isformed on an outer circumferential surface of a distal end of the covermember, and the cover member is screw-coupled to the circular flange ofthe case to be detachably installed thereat wherein a female screwthread is formed on an inner circumferential surface of the circularflange of the case.

The cover member may have a structure in which a handle is formed toprotrude from the cover member to allow the cover member to be rotatedagainst the case.

The sealing member may be in a ring form in which a hole is formed toexpose the cathode part of the coin-type secondary battery, and may havea structure in which an inner circumferential surface of the sealingmember is processed and stepped to correspond to the outer circumferenceof the coin-type secondary battery to surround the outer circumferencethereof.

The sealing member may be formed of a silicone material.

The anode terminal may include an anode rod installed to pass throughthe interior of the case and be electrically connected to the anode partof the coin-type secondary battery.

The anode terminal may further include an electrode plate installed atthe seating part of the case to be brought into contact with the anodepart of the coin-type secondary battery, and the anode rod may have astructure which is electrically connected to the anode part of thecoin-type secondary battery through the electrode plate.

The anode terminal may have a structure in which the anode rod is formedin a bolt shape and is screw-coupled to the case to pressurize theelectrode plate such that the electrode plate is brought into closecontact with the anode part of the coin-type secondary battery.

The cathode terminal may include a cathode rod installed to pass throughthe interior of the cover member and be electrically connected to thecathode part of the coin-type secondary battery.

The cathode terminal may further include carbon felt disposed betweenthe cathode rod and the cathode part of the coin-type secondary batteryand configured to come into contact with the cathode part.

The cathode rod may have a structure in which a distal end of thecathode rod in contact with the cathode part of the coin-type secondarybattery is wound in a coil form to constitute a coil spring configuredto apply an elastic force between the cover member and the cathode part.

The cathode rod may be formed of a titanium material.

The charging and discharging apparatus may further include an oxygensupplier configured to supply oxygen to the solution.

The oxygen supplier may include a circulation pipe connected to thevessel in which the solution is accommodated to discharge the solution;a pump connected to the circulation pipe and configured to circulate thesolution; and a discharge pipe connected to an outlet side of the pumpand extending above the vessel to discharge the solution dischargedthrough the pump over the solution of the vessel.

Advantageous Effects

In accordance with one embodiment of the present invention, a solidelectrolyte selectively passing a specific metal ion is applied to ananode part of a coin-type secondary battery, and an ion-containingsolution flowing from the outside and containing sodium, lithium,magnesium, and a combination thereof, which are eco-friendly and safematerials, is used in a cathode part thereof, and thus an ocean, inwhich seawater, among ion-containing solutions, is abundant, can beselected as a suitable site for installing a large-scale storage system,so that a coin-type secondary battery capable of reducing costs forinstallation and in which environmental problems may be relatively lesscaused can be provided.

In accordance with another embodiment of the present invention, a methodfor manufacturing a coin-type secondary battery which is advantageousfor commercialization and mass production with a simplifiedmanufacturing process can be provided.

In accordance with the embodiments, charging and discharging of thecoin-type secondary battery can be more easily performed.

In accordance with the embodiments, the cathode part and the anode partof the coin-type secondary battery are properly separated from eachother such that a short-circuit between the anode part and the cathodepart caused by seawater can be reliably prevented.

In accordance with the embodiments, assembly of the coin-type secondarybattery can be easily performed, and a charge and discharge test for thecoin-type secondary battery can be easily performed. Therefore, variouscharge and discharge tests for the coin-type secondary battery can bemore easily performed.

DESCRIPTION OF DRAWINGS

FIGS. 1 and 2 are each a diagram schematically illustrating a side viewof a portion of a coin-type secondary battery according to oneembodiment of the present invention.

FIG. 3 is a diagram schematically illustrating a side view of acoin-type secondary battery manufactured according to one embodiment ofthe present invention.

FIGS. 4 and 5 are diagrams schematically illustrating a side view of aportion of an anode part included in the coin-type secondary batteryaccording to one embodiment of the present invention.

FIG. 6 is a graph illustrating a charge and discharge characteristicevaluation of the coin-type secondary battery according to oneembodiment of the present invention.

FIG. 7 is a perspective view of an apparatus for charging anddischarging a coin-type secondary battery according to the presentembodiment.

FIG. 8 is an exploded perspective view illustrating a configuration ofthe apparatus for charging and discharging a coin-type secondary batteryaccording to the present embodiment.

FIG. 9 is a schematic cross-sectional view of the apparatus for chargingand discharging a coin-type secondary battery according to the presentembodiment.

FIG. 10 is a schematic cross-sectional view of an apparatus for chargingand discharging a coin-type secondary battery according to anotherembodiment.

MODES OF THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail. However, these embodiments are illustrative, and the presentinvention is not limited thereto and is only defined by the scope of theappended claims.

In one embodiment of the present invention, there is provided acoin-type secondary battery including an anode part; a cathode part; aseparator disposed between the anode part and the cathode part; a firstcase disposed outside the anode part; and a second case disposed outsidethe cathode part and including at least one opening, wherein the firstcase and the second case are bonded to each other; the anode part, theseparator, and the cathode part are sealed by the first case and thesecond case which are bonded; the anode part includes an anode bottomcase, an anode current collector disposed on the anode bottom case, andan anode upper case to which one or more solid electrolytes are bonded;the anode upper case includes one or more openings; the one or moresolid electrolytes are disposed at the one or more openings in the anodeupper case, respectively; the cathode part includes an ion-containingsolution containing sodium, lithium, magnesium, and a combinationthereof, and a cathode current collector impregnated with theion-containing solution; and the ion-containing solution flows into thecathode part from the outside of the second case through the one or moreopenings of the second case.

In this regard, FIG. 1 schematically shows a side view of the coin-typesecondary battery. Meanwhile, the coin-type secondary battery mayinclude a single cathode part, as shown in FIG. 1, and may include twocathode parts, as shown in FIG. 2.

Specifically, the coin-type secondary battery shown in FIG. 1 isactually implemented in the form of FIG. 3 in one embodiment of thepresent invention. More specifically, referring to FIG. 3, the coin-typesecondary battery includes an anode part in which an anode bottom case1, an anode current collector 2, an anode plate spacer 3, an anodeactive material 4, an in-anode separator 5, a solid electrolyte 6, andan anode upper case 8 are sequentially stacked in the anode part, and acathode part in which a cathode catalyst electrode 10 and a cathodecurrent collector 11 are sequentially stacked, and a separator 9, whichis a non-electric conductive diaphragm, is disposed between the anodepart and the cathode part to prevent a short circuit therebetween.Further, the anode part and the cathode part are sealed by a first case13 and a second case 12 which are bonded to each other.

Specifically, one or more openings are provided in the second case 12 sothat an ion-containing solution may flow from the outside of thecoin-type secondary battery into the cathode part through the one ormore openings of the second case. In FIG. 3, a case in which threeopenings are provided in the second case 12 is exemplified, but thepresent invention is not limited thereto.

Further, one or more openings may be provided in the anode upper case 8,the solid electrolyte 6 may be bonded to the one or more openings of theanode upper case 8, and the anode upper case 8 and the solid electrolyte6 may be bonded by an adhesive (not shown). In FIG. 3, a case in whichone opening is provided in the anode upper case 8 is exemplified, butthe present invention is not limited thereto.

Meanwhile, a liquid electrolyte (not shown) may be included in the anodepart, and the anode current collector 2, the anode plate spacer 3, theanode active material 4, the in-anode separator 5, and the solidelectrolyte 6 may be impregnated with the liquid electrolyte (notshown). Further, a gasket 7 may be disposed in a space between the anodebottom case 1 and the anode upper case 8, and the gasket 7 may serve toprotect inner materials thereof and prevent leakage of the liquidelectrolyte (not shown) injected into the anode part.

Hereinafter, components of the coin-type secondary battery will bedescribed with reference to FIGS. 1 and 3.

The anode part will be described as follows first.

The anode part includes the anode current collector between the anodebottom case and the anode upper case including the one or more openings,and the solid electrolyte is bonded to each of the one or more openingsof the anode upper case.

As described above, the one or more solid electrolytes are applied tothe anode part such that the battery can be stably driven by specificmetal ions selectively passing therethrough. At this point, the solidelectrolyte is applied in a form shown in FIG. 4.

Specifically, FIG. 4 schematically shows a portion of the solidelectrolyte bonded to each of the openings in the anode upper case whenviewed from a side thereof. Although a case in which a single opening inthe anode upper case and a single solid electrolyte are provided isshown in FIG. 4, a bonded form may be determined with reference to thefact that one or more openings and one or more solid electrolytes areprovided in the anode upper case.

In FIG. 4, the opening is disposed in the anode upper case, and a solidelectrolyte having a size that is greater than that of the opening isdisposed at a rear surface of the anode upper case and is exposed at afront surface of the anode upper case by the opening thereof.

It may be determined that the solid electrolyte is exposed by theopening of the anode upper case with reference to the above description.As described above, the exposed portion of the solid electrolyte may bea path through which a specific metal ion selectively passes, and thesolid electrolyte may be formed to have an area that is larger than thatof a conventionally known solid electrolyte.

Meanwhile, the anode part may be disposed over the solid electrolytedisposed at each of the openings in the anode upper case, and the anodepart may further include an adhesive bonding the solid electrolyte tothe anode upper case.

FIG. 5 schematically shows a portion of a side view when the solidelectrolyte is bonded to the anode upper case by the adhesive.Specifically, in FIG. 5, a case in which a single opening in the anodeupper case and a single solid electrolyte are provided is shown.

Referring to FIG. 5, it can be seen that a form in which the adhesivebonds the solid electrolyte to the anode upper case is not limited to aspecific form as long as the adhesive bonds the solid electrolyte to theanode upper case while being disposed to cover a portion of the solidelectrolyte.

More specifically, the adhesive may include one or more materialsselected from the group consisting of a silicon (Si) based material, anepoxy based material, and a combination thereof.

Meanwhile, the solid electrolyte is not limited to a material whichselectively passes specific metal ions (e.g., Lit, Nat, and the like).Specifically, the solid electrolyte may be a material through which themetal ions selectively passes at a high rate and in which an interfacewith an aqueous solution and an organic solution is stably formed.

For example, the solid electrolyte may be selected from the groupcomprising a Na superionic conductor (NASICON), a Li superionicconductor (LISICON), an amorphous ion conductive material, a ceramic ionconductive material, and a combination thereof.

Specifically, examples of the amorphous ion conductive material mayinclude a phosphorus-based glass, an oxide-based glass, anoxide/sulfide-based glass, and the like.

Further, examples of the ceramic ion conductive material may includelithium beta-alumina, sodium beta-alumina, and the like.

More specifically, when a NASICON is selected as the solid electrolyte,ion conductivity of the solid electrolyte can be further improved.

On the other hand, the anode part may further include a conductivepolymer membrane disposed to cover the adhesive while being adjacent tothe solid electrolyte. In this case, electron conductivity can beimproved by the conductive polymer membrane.

The polymer contained in the conductive polymer membrane is notparticularly limited as long as the polymer has conductivity. Forexample, the polymer may be a polymer selected from the group consistingof a polyacetylene-based polymer, a polypyrrole-based polymer, apolyaniline-based polymer, a polyphenylene sulfide (PPS) based polymer,a polythiophene-based polymer, a PEDOT-based polymer, and the like.

The anode part may further include an anode active material layerdisposed over the anode current collector, and the anode active materiallayer may include an anode active material, and the anode activematerial may be one or more materials selected from the group consistingof a metal, a metal oxide, a metal sulfide, a metal phosphide, acarbon-based material, and a combination thereof.

For example, sodium (Na), tin (Tn), antimony (Sb), bismuth (Bi), alloysthereof, oxides thereof, sulfides thereof, or phosphides thereof can beselected as the anode active material, and an anode active material suchas a carbon-based material or a mixture of the above-describedmaterials, which are generally known in the art, can also be selected.

Meanwhile, the anode active material layer may include the anode activematerial, a conductive material, and/or a binder. The conductivematerial is used to impart conductivity, and any material may be used aslong as the material has electron conductivity without causing achemical change in a battery which is constituted thereby. Further, thebinder may employ any material as long as the binder serves to adhereparticles of the anode active material to each other, and the anodeactive material to the anode current collector.

The anode part may further include a liquid electrolyte.

The liquid electrolyte may include a dissociable salt and an organicsolvent.

At this point, the organic solvent acts as a medium through which ionsinvolved in an electrochemical reaction of the battery may move. Forexample, the organic solvent may be one or more materials selected fromthe group consisting of an ether-based organic solvent, acarbonate-based organic solvent, a nitrile-based organic solvent, and acombination thereof.

More specifically, examples of the ether-based organic solvent mayinclude tri-ethylene glycol-di-methyl ether (TEGDME) and the like,examples of the carbonate-based organic solvent may include propylenecarbonate (PC), ethyl-methylene carbonate (EMC), di-methylene carbonate(DMC), ethylene carbonate (EC), and the like, and examples of thenitrile-based organic solvent may include acetonitrile (ACN) and thelike.

Further, the dissociable salt is a material that is dissolved in theorganic solvent and acts as a supply source of cations in a battery,thereby serving to enable a basic operation of a secondary battery andpromote movement of the cations between a cathode and an anode. Forexample, the dissociable salt may be one or more materials selected fromthe group consisting of a sodium compound, a lithium compound, anammonium compound, and a combination thereof.

More specifically, examples of the sodium compound may include NaCF₃SO₃,NaPF₆, NaBF₄, and the like, examples of the lithium compound may includeLiPF₆, LiBF₄, LIClO₄, and the like, and examples of the ammoniumcompound may include Et₄NBF₄, Et₄NPF₆, and the like.

Each of the anode bottom case and the anode upper case may be made of ametal, such as steel use stainless (SUS), aluminum (Al), or steel, or anonferrous metal. At this point, each of the anode bottom case and theanode upper case may be in a coin form having a diameter in a range of 2cm to 10 cm and a thickness in a range of 0.1 to 2.0 t. Further, theanode upper case may include one or more openings, as described above,and each of the one or more openings of the anode upper case may have adiameter in a range of 0.5 cm to 9 cm.

As described above, the size of the solid electrolyte may be larger thanthat of the opening of the anode upper case. Conversely, when the sizeof the solid electrolyte is smaller than that of the opening, the solidelectrolyte may be separated from the anode upper case through theopening without being bonded thereto. Specifically, each of the solidelectrolytes bonded to the anode upper case may have a diameter in arange of 1 cm to 10 cm, and the form of each of the solid electrolytesis not limited to that described above.

The anode current collector may be made of a nonferrous metal such as acopper foil, a nickel foil, a stainless steel foil, a titanium foil, anickel foam, a copper foam, a polymer base material coated with aconductive metal, or the like. At this point, the anode currentcollector may be in a coin form having a diameter in a range of 1 cm to9 cm and a thickness in a range of 0.1 to 2.0 t.

The cathode part will be described as follows.

In the cathode part, the ion-containing solution containing sodium,lithium, magnesium, and a combination thereof may be selected from thegroup consisting of seawater, salty water and a combination thereof.

Specifically, when seawater is selected as the ion-containing solution,an installation site of the coin-type secondary battery may be the sea,and thus seawater may flow from the outside of the second case into thecathode part through the opening of the second case. In this case, thecoin-type secondary battery may be suitable for installation as alarge-scale storage system so that costs for the installation can bereduced and environmental problems can be relatively less caused.

Meanwhile, the cathode current collector may be in a coin form having adiameter in a range of 1 cm to 9 cm and a thickness in a range of 0.1 to2.0 t. Further, a carbon paper, a carbon fiber, a carbon cloth, carbonfelt, a metal thin film, or a combination thereof may be used as thecathode current collector. The carbon paper may minimize a by-productthat may be generated by oxidation and reduction reactions of othermetal ions contained in the sodium-containing solution.

Further, when a catalyst electrode is disposed on the cathode currentcollector, reactivity thereof can be further improved. Specifically, thecathode part may further include a catalyst electrode disposed on thecathode current collector, and the catalyst electrode may be made of onematerial selected from the group consisting of a metal oxide, a novelmetal material, a carbon-based material, a perovskite-based material,and a combination thereof.

More specifically, examples of the metal oxide may include RuO₂, MnO₂,Co₃O₄, TiO₂, LiCoO₂, Ni(OH)₂, and the like, examples of the novel metalmaterial may include Pt, Ag, Au, and the like, examples of acarbon-based catalyst may include graphene oxide, a carbon paper, carbonfelt, a carbon nano tube, a graphene, carbon nano wire, and the like,and the perovskite-based material may be an oxide represented by theformula ABOx.

Hereinafter, the remaining components included in the coin-typesecondary battery will be described, and components that are notdescribed below are generally known in the art.

Materials such as plastic, acryl, polyether ether ketone (PEEK), Teflon,engineering plastic, PC, and the like may be used as the first case andthe second case. At this point, each of the first case and the secondcase may be in a quadrangular form having a width and a length in arange of 4 cm to 30 cm and a thickness in a range of 0.5 to 5.0 t.

Further, the second case may include the one or more openings, asdescribed above, and a diameter of each of the one or more openings inthe second case may be in a range of 1 cm to 9 cm, and a shape of eachof the one or more openings is not limited.

In this regard, the coin-type secondary battery may further include abonding part configured to bond the first case to the second case.Materials such as plastic, acryl, PEEK, Teflon, engineering plastic, PC,and the like may be used as the bonding part.

Materials such as a polymer, a paper, cellulose, and the like may beused as the separator, and the separator may be in a coin form having adiameter in a range of 1 cm to 9 cm and a thickness in a range of 0.1 to2.0 t.

Meanwhile, the anode part may further include a plate spacer, and theplate spacer serves to connect the anode current collector to the anodebottom case while fixing the anode active material in the anode part. Atthis point, the plate spacer may be in a coin form having a diameter ina range of 1 cm to 9 cm and a thickness in a range of 0.1 to 2.0 t.

According to another embodiment of the present invention, there isprovided a method for manufacturing a coin-type secondary battery, themethod including bonding one or more solid electrolytes to an anodeupper case; forming an anode active material layer on an anode currentcollector; sequentially stacking the anode current collector and theanode upper case to which the one or more solid electrolytes are bondedon an anode bottom case to obtain an anode part; sequentially stackingthe anode part, a separator, a cathode current collector, and a secondcase including one or more openings on a first case; bonding the firstcase to the second case; and introducing an ion-containing solutioncontaining sodium, lithium, magnesium, and a combination thereof fromthe outside into the second case, wherein, in the bonding of the one ormore solid electrolytes to the anode upper case, one or more openingsare disposed in the anode upper case, and the one or more solidelectrolytes are bonded to the one or more openings in the anode uppercase; and, in the introducing of the ion-containing solution containingsodium, lithium, magnesium, and a combination thereof from the outsideof the second case, the ion-containing solution flows into the cathodepart from the outside of the second case through the one or moreopenings of the second case.

This is accomplished by a simplified method including manufacturing theanode part including the anode upper case after manufacturing the anodeupper case to which the solid electrolyte is bonded; independentlypreparing each of the components; stacking each of the components in theabove-described order; and introducing the ion-containing solution intothe cathode part from the outside of the second case, and thus the abovemethod is advantageous when commercializing and mass producing theabove-described coin-type secondary battery.

Specifically, to realize the coin-type secondary battery as alarge-scale storage system, an ocean, at which seawater, amongion-containing solutions, is abundant, may be selected as a suitablesite for installing the coin-type secondary battery such that costs forinstallation can be reduced and environmental problems can be relativelyless caused.

In addition, as described above, the coin-type secondary battery may befinally obtained by the components and the manufacturing method, and themanufacturing method can be more clearly understood through thefollowing embodiments.

Hereinafter, each of operations for manufacturing the coin-typesecondary battery will be described in detail.

First, as described above, the manufacturing of the anode part includesbonding the one or more solid electrolytes to the anode upper case;forming the anode active material layer on the anode current collector;and sequentially stacking the anode current collector and the anodeupper case to which the one or more solid electrolytes are bonded on theanode bottom case to obtain the anode part.

Specifically, in the bonding of the one or more solid electrolytes tothe anode upper case, the one or more openings may be disposed in theanode upper case, and the one or more solid electrolytes may be bondedto the one or more openings in the anode upper case.

More specifically, the bonding of the one or more solid electrolytes tothe anode upper case may bond the one or more solid electrolytes to theanode upper case using an adhesive.

The bonding may be performed by a heat treatment, and the heat treatmentmay be performed at a temperature in a range of 150° C. to 200° C. for 1to 30 minutes.

At this point, the adhesive may include one or more materials selectedfrom the group consisting of a silicon (Si) based material, anepoxy-based material, and a combination thereof.

The solid electrolyte may be selected from the group consisting of aNASICON, a LISICON, an amorphous ion conductive material, a ceramic ionconductive material, and a combination thereof.

In addition, the form in which the one or more solid electrolytes arebonded to the anode upper case by the adhesive is identical to theabove-described form.

The above-described anode active material layer may be formed on asurface of the anode current collector, and the anode active materiallayer is manufactured by mixing an anode active material, a binder, anda conductive material in a solvent for manufacturing an active materialcomposition, and applying the active material composition to a currentcollector. Such an electrode manufacturing method is well known in theart, and thus a detailed description thereof will be omitted herein.N-methylpyrrolidone or the like may be used as the solvent, but thepresent invention is not limited thereto.

As described above, after the manufacturing of the anode part isperformed, the sequential stacking of the anode part, the separator, thecathode current collector, and the second case including the one or moreopenings may be performed.

As a result of performing the sequential stacking, a detailed order inwhich each of the components is stacked while performing the sequentialstacking is not limited as long as the stacked structure in theabove-described order can be obtained.

For example, as in an embodiment which will be described below, afterdisposing the manufactured anode part on the first case, the detailedorder of the stacking may include disposing the separator on the anodepart disposed on the first case, disposing the catalyst electrodethereon, disposing the cathode current collector on the catalystelectrode, and then disposing the second case thereon, but the presentinvention is not limited to the detailed order of the stacking.

The anode part and the cathode part may be sealed by the first case andthe second case which are bonded through the bonding of the first caseand the second case. At this point, as described above, the bonding maybe performed by the bonding part.

The introducing of the ion-containing solution containing sodium,lithium, magnesium, and a combination thereof into the second case fromthe outside thereof is performed that the ion-containing solution flowsinto the cathode part from the outside of the second case through theopening in the second case, and thus this process may include bondingthe first case and the second case and then immersing the first case andthe second case, which are bonded, into the ion-containing solution.Through such operations, the ion-containing solution may be present atan outer side of each of the first case and the second case, and thusthe ion-containing solution may flow from the outside of the second caseinto the cathode part.

Hereinafter, preferred examples of the present invention will bedescribed. However, the following examples are merely one preferredembodiment of the present invention, and the present invention is notlimited to the following examples.

Example 1: Manufacture of Coin-Type Secondary Battery

To manufacture the coin-type secondary battery shown in FIG. 3, after ananode part was manufactured, a series of processes of disposing theanode part on a first case, disposing a separator on the anode partdisposed on the first case, disposing a catalyst electrode on theseparator, disposing a cathode current collector on the catalystelectrode, and disposing a second case thereon were performed.Hereinafter, the processes will be described in detail.

(1) Manufacture of Anode Part

As will be described below, the process of manufacturing the anode partwas performed by manufacturing each of an assembled anode upper case andan assembled anode bottom case and then bonding the anode upper case andthe anode bottom case to each other.

1) Manufacture of Assembled Anode Bottom Case

A welded plate spacer was manufactured by welding an anode currentcollector (having a diameter of Φ10 mm) onto a plate spacer (having adiameter of Φ19 mm). An assembled anode plate was manufactured by fixingan anode active material onto the welded plate spacer.

At this point, a sodium metal was used as the anode active material, andthe anode active material was press-fixed onto the welded plate spacer.

Subsequently, a metal foam spacer (having a width of 4 mm and a lengthof 4 mm), the assembled anode plate, and an anode separator (having adiameter of 20 mm) were sequentially placed on an anode bottom case(having a diameter of Φ19 mm), and then a predetermined amount of aliquid electrolyte (e.g., a NaCF₃SO₃ solution) was injected therein tomanufacture the assembled anode bottom case.

2) Manufacture of Assembled Anode Upper Case

Independently, an assembled anode upper case was manufactured by bondinga solid electrolyte to an opening of an anode upper case (i.e., apunched anode upper case having a diameter of Φ20 mm) using asilicone-based adhesive.

Specifically, the number of openings in the anode upper case and thenumber of the solid electrolytes are each one.

Also, during the bonding, the anode upper case at which the opening wasformed was disposed on one side of the solid electrolyte, and the solidelectrolyte was bonded to the anode upper case by applying heat with atemperature of 180° C. thereto for 10 minutes.

3) Manufacture of Anode Part

The assembled anode bottom case and the assembled anode upper case werepressed and fixed to each other to complete the anode part. At thispoint, the press-fixing was performed using a crimper.

(2) Manufacture of Coin-Type Secondary Battery

The completed anode part was fixed to a first case (having a width of 4cm and a length of 4 cm) made of a plastic material. A separator (havinga diameter: Φ19 mm) made of a polymer and a carbon-based catalystelectrode were sequentially disposed on the anode part fixed to thefirst case, and then the carbon-based catalyst electrode was coveredwith a second case (having a width of 4 cm and a length of 4 cm).

Specifically, a second case in which three openings were formed wasused.

Subsequently, the first case and the second case were bonded using aplastic fix bar made of a plastic material as a bonding part, and wereimmersed in seawater (purchased from Sigma-Aldrich) to allow theseawater to flow into the first case and the second case through theopening of the second case, thereby completing the coin-type secondarybattery.

Evaluation Example 1: Evaluation of Electrochemical Characteristic ofCoin-Type Secondary Battery

Electrochemical evaluation was performed five times on the coin-typesecondary battery of Example 1.

Specifically, the evaluation results according to each of theevaluations are shown below in Table 1.

TABLE 1 Evaluation Results Open Circuit Evaluation Voltage ChargeDischarge Ohmic Columbic Times (OCV) Voltage Voltage ResistanceEfficiency 1 2.85 V 3.80 V 2.78 V 58.3 Ω 93% 2 2.91 V 3.83 V 2.81 V 59.4Ω 95% 3 2.87 V 3.79 V 2.79 V 58.1 Ω 94% 4 2.90 V 3.81 V 2.80 V 59.3 Ω92% 5 2.88 V 3.77 V 2.78 V 58.2 Ω 90%

Specifically, as shown in Table 1 and FIG. 6, as a result of chargingand discharging the coin-type secondary battery of Example 1 inseawater, an open circuit voltage (OCV), a charging voltage, a dischargevoltage, and resistance were each measured, and coulombic efficiency wascalculated on the basis of these measured values. Thus, it can be seenthat the coin-type secondary battery of Example 1 exhibited superiorcoulombic efficiency of 90% or more.

Meanwhile, an apparatus for charging and discharging a coin-typesecondary battery will be described below.

FIG. 7 shows an exterior of the apparatus for charging and discharging acoin-type secondary battery according to the present embodiment. FIG. 8shows an exploded structure of the apparatus for charging anddischarging a coin-type secondary battery, and FIG. 9 shows across-sectional structure of the apparatus for charging and discharginga coin-type secondary battery in a coupled state.

Hereinafter, components of the apparatus for charging and discharging acoin-type secondary battery will be described with reference to FIGS. 7to 9.

A charging and discharging apparatus 100 of the present embodimentincludes a vessel 110 filled with a solution containing water or sodiumions, and a jig part 120 installed at the vessel 110, in which acoin-type secondary battery 200 is installed, and configured to allow acathode part 210 of the coin-type secondary battery 200 to come intocontact with the solution in the vessel 110.

Further, to connect a load such as a current or a resistor to thecoin-type secondary battery 200, the charging and discharging apparatus100 may further include an anode terminal installed at the jig part 120and electrically connected to an anode part 220 of the coin-typesecondary battery 200, and a cathode terminal electrically connected tothe cathode part 210 of the coin-type secondary battery 200.

Thus, the cathode part 210 of the coin-type secondary battery 200 isbrought into contact with the solution, and a current is applied to thesecondary battery 200 or a resistor is connected thereto such that thesecondary battery 200 may be charged and discharged. Here, for example,the coin-type secondary battery 200 may be understood as being a batteryin a state in which a first case and second case thereof are removed tofacilitate charging and discharging.

The solution may be a solution, e.g., seawater, containing sodiumrequired for charging the coin-type secondary battery 200. Further, whenthe coin-type secondary battery 200 is discharged, an aqueous solutioncontaining water may be applied thereto as the solution in addition tothe solution containing sodium. For example, seawater used for chargingmay be used for discharging, and, alternatively, only water may be usedas the solution.

A solution accommodation space is formed inside the vessel 110, and anupper end of the vessel 110 is open to enable the solution to besupplied thereto or discharged therefrom. A size and form of the vessel110 may be variously modified and are not particularly limited. Thevessel 110 may be made of a material that is not corroded or deformed byseawater so that seawater may be accommodated therein.

A hole is formed to pass through one side of the vessel 110 and becoupled to the jig part 120. Thus, the jig part 120 is coupled to thehole of the vessel 110 to bring the cathode part 210 of the coin-typesecondary battery 200 into contact with the solution. In the presentembodiment, the jig part 120 is detachably coupled to the hole of thevessel 110. Accordingly, the jig part 120 at which the coin-typesecondary battery 200 is installed may be separated from the vessel 110accommodating the seawater to more easily install the secondary battery200 at the jig part 120. An attachment and detachment structure of thejig part 120 with respect to the vessel 110 will be described in moredetail below.

The jig part 120 allows only the cathode part 210 of the coin-typesecondary battery 200 to be in contact with the solution accommodatedinside the vessel 110.

To this end, the jig part 120 includes a case 130 installed at thevessel 110 and having a seating part 132 formed at a front surface ofthe case 130 facing an interior of the vessel 110 and the seating part132 at which the coin-type secondary battery 200 is seated; a sealingmember 140 installed to surround an outer circumference of the coin-typesecondary battery 200 and coupled inside the case 130 to seal betweenthe anode part 220 of the coin-type secondary battery 200 and the case130 and block the solution from flowing into the anode part 220; and acover member 150 coupled to the front surface of the case 130,configured to pressurize the sealing member 140 such that the sealingmember 140 is brought into close contact with the front surface, andhaving a hole 152 formed at a front surface of the cover member 150 toexpose the cathode part 210 of the coin-type secondary battery 200.

Thus, the anode part 220 of the coin-type secondary battery 200 issealed in the case 130 by the sealing member 140 in close contactbetween the case 130 and the cover member 150 so that only the cathodepart 210 is brought into contact with the solution of the vessel 110through the hole 152 of the cover member 150, and thus the solution isblocked from flowing into the anode part 220.

The case 130 may be configured with a circular cross-sectional structurelike the coin-type secondary battery 200. The form of the case 130 maybe variously modified and is not limited to a circular form. The seatingpart 132 is formed as a recess at a center of the front surface of thecase 130, which communicates with the interior of the vessel 110, toallow the secondary battery 200 to be seated at the seating part 132.Further, a flange 134 is formed to protrude from the case 130 tosurround the seating part 132 along an outer circumference of the frontsurface thereof.

The case 130 may be installed at the vessel 110 in a screw-coupledmanner A male screw thread is formed on an outer circumferential surfaceof the circular flange 134 formed along the outer circumference of thefront surface of the case 130, and a hole formed at a side surface ofthe vessel 110 constitutes a female thread hole 112 having a femalescrew thread formed on an inner circumferential surface thereof suchthat the flange 134 of the case 130 may be screw-coupled to andinstalled at the female thread hole 112.

A ring member 114 for sealing may be installed at the flange 134 of thecase 130 to prevent leakage of the solution between the flange 134 ofthe case 130 and the female thread hole 112 of the vessel 110 such thata structure sealing between the case 130 and the vessel 110 may beconfigured thereby.

Thus, the jig part 120 may allow the flange 134 of the case 130 to bescrew-coupled to the female thread hole 112 of the vessel 110 and easilyattached to or detached from the case 130.

The jig part 120 is mounted on the vessel 110 and accommodates thecoin-type secondary battery 200 to be charged and discharged inside thejig part 120. The coin-type secondary battery 200 is disposed inside theflange 134 of the case 130, and is fixed by the cover member 150 coupledto the flange 134 of the case 130.

The cover member 150 is configured with a circular cross-sectionalstructure. The cover member 150 is configured with a structure in whichan interior into which the sealing member 140 is fittable is providedand the hole 152 is formed to pass through a central portion of thefront surface of the cover member 150.

The cover member 150 may be attached to the flange 134 of the case 130in a screw-coupling manner. The cover member 150 may be configured witha structure in which a male screw thread is formed on an outercircumferential surface of a distal end of the cover member 150, and afemale screw thread is formed on an inner circumferential surface of theflange 134 of the case 130 so that the cover member 150 is screw-coupledto the flange 134 of the case 130 to be detachably installed at theflange 134 of the case 130.

Thus, the cover member 150 may be screw-coupled to the flange 134 of thecase 130 to be easily attached to or detached from the case 130.

A handle 154 is formed to protrude from the cover member 150 to allowcover member 150 to be rotated with respect to the case 130. The handle154 has a structure lengthy extending and passing a central axis of thecover member 150, and is formed across the hole 152 formed at thecentral portion of the cover member 150. The handle 154 is formed tohave a thickness that is sufficiently smaller than a diameter of thehole 152 formed at the cover member 150 to not interfere with the hole.Accordingly, even though the handle 154 is formed across the hole 152,the hole 152 is not blocked by the handle 154 and communicates with theoutside.

The sealing member 140 is configured with a structure constituting aring form in which a hole 142 is formed to expose the cathode part 210of the coin-type secondary battery 200, and in which an innercircumferential surface of the sealing member 140 is processed andstepped to correspond to the outer circumference of the coin-typesecondary battery 200 to surround the outer circumference thereof. Inthe present embodiment, the sealing member 140 may be formed of asilicon material.

As shown in FIG. 9, the sealing member 140 is pressurized by the covermember 150 inside the flange 134 of the case 130 to seal the anode part220 of the secondary battery 200. When the cover member 150 is attachedto the case 130, the sealing member 140 surrounding the coin-typesecondary battery 200 is brought into close contact between the case 130and the cover member 150 such that the sealing member 140 seals betweenthe anode part 220 of the coin-type secondary battery 200 and the case130. Consequently, a flow of the solution toward the secondary battery200 through the hole 152 of the cover member 150 is blocked by thesealing member 140 such that the solution does not move to the anodepart 220 of the secondary battery 200.

To charge and discharge the coin-type secondary battery 200 mounted onthe jig part 120, a current or load should be connected to the coin-typesecondary battery 200. Thus, the cathode terminal and the anode terminalare provided at the jig part 120 to be electrically connected to thecathode part 210 and the anode part 220 of the coin-type secondarybattery 200 disposed inside the jig part 120.

The anode terminal may include an anode rod 160 installed to passthrough an interior of the case 130 and electrically connected to theanode part 220 of the coin-type secondary battery 200.

The anode rod 160 is configured in the form of a long extending bar, andpasses through the center of the case 130 from the outside thereof toextend to the interior of the case 130. Thus, the anode part 220 of thesecondary battery 200 is electrically connectable to the outside of thecase 130 through the anode rod 160.

The anode terminal may further include an electrode plate 162 installedat the seating part 132 of the case 130 to be in contact with the anodepart 220 of the coin-type secondary battery 200, and the anode rod 160may be configured with a structure electrically connected to the anodepart 220 of the coin-type secondary battery 200 through the electrodeplate 162.

The electrode plate 162 has a circular plate structure and has a recessformed to allow the anode part 220 of the coin-type secondary battery200 to be bonded to the electrode plate 162. The seating part 132 of thecase 130 may be formed to have a size corresponding to an exterior ofthe electrode plate 162.

Accordingly, the anode part 220 of the coin-type secondary battery 200may be electrically connected to the anode rod 160 through the electrodeplate 162, and a current or load may be connected to the anode part 220of the secondary battery 200 through the anode rod 160 extending to theoutside of the case 130.

In the present embodiment, the anode terminal may have a structure inwhich the electrode plate 162 is pressurized against the anode part 220of the secondary battery 200.

To this end, the anode terminal is configured with a structure in whichthe anode rod 160 is in a bolt form and is screw-coupled to the case130. Accordingly, when the anode rod 160 is rotated and tightenedagainst the case 130, the anode rod 160 pressurizes the electrode plate162 such that the electrode plate 162 is brought into close contact withthe anode part 220 of the coin-type secondary battery 200.

As described above, the anode rod 160 is tightened to pressurize theelectrode plate 162, and thus the secondary battery 200 pressurized bythe electrode plate 162 is brought into closer contact with the sealingmember 140 in the case 130 such that a sealing effect thereof can befurther enhanced.

The cathode terminal may include a cathode rod 170 installed to passthrough an interior of the cover member 150 and be electricallyconnected to the cathode part 210 of the coin-type secondary battery200.

In the present embodiment, since the cathode rod 170 is in contact withthe solution such as seawater and the like, the cathode rod 170 may beformed of a titanium material that is not corroded by seawater.

The cathode rod 170 is in the form of a long extending bar, and passesthrough the handle 154 formed at the cover member 150 from the outsidethereof to extend to the interior of the case 130. Thus, the cathodepart 210 of the secondary battery 200 is electrically connectable to theoutside of the cover member 150 through the cathode rod 170. An outerdistal end of the cathode rod 170 may extend above the vessel 110 to beexposed over the solution accommodated in the vessel 110.

In the present embodiment, the cathode terminal may further includecarbon felt 172 installed between the cathode rod 170 and the cathodepart 210 of the coin-type secondary battery 200 to be in contact withthe cathode part 210. The carbon felt 172 is formed to have a diametercorresponding to a diameter of the hole 142 of the sealing member 140,and is disposed on the hole to be in contact with the cathode part 210.

The carbon felt 172 is brought into contact with the cathode part 210 ofthe coin-type secondary battery 200 to serve as a current collector ofthe cathode part 210.

Further, the cathode terminal is configured with a structure tightlypressurizing the carbon felt 172 to allow the carbon felt 172 to bebrought into closer contact with the cathode part 210 of the coin-typesecondary battery 200. To this end, the cathode rod 170 may have astructure in which a distal end of the cathode rod 170, which is broughtinto contact with the cathode part 210 of the coin-type secondarybattery 200, is wound in a coil form to constitute a coil spring 174configured to apply an elastic force between the cover member 150 andthe cathode part 210. A diameter of the coil spring 174 is notparticularly limited as long as the coil spring 174 can pressurize thecarbon felt 172.

As described above, the coil spring 174 constituting the inner distalend of the cathode rod 170 applies the elastic force to the carbon felt172 in a state of being engaged with and supported by the handle 154 ofthe cover member 150, thereby tightly pressurizing the carbon felt 172toward the cathode part 210 of the secondary battery 200. Consequently,the carbon felt 172 is brought into close contact with the cathode part210 such that a current collecting effect thereof can be enhanced.

FIG. 10 shows another embodiment of the apparatus for charging anddischarging a coin-type secondary battery.

The charging and discharging apparatus 100 of the present embodiment isconfigured with a structure circulating a solution in the vessel 110 tosupply oxygen to the solution. Since the structure of the charging anddischarging apparatus of the present embodiment is the same as that ofthe other embodiments except for the oxygen supply structure, the samereference numerals will be assigned to the components which have beendescribed in the following description, and thus detailed descriptionsthereof will be omitted.

As shown in FIG. 10, the charging and discharging apparatus 100 of thepresent embodiment further includes an oxygen supplier 230 configured tosupply oxygen to the solution of the vessel 110.

Oxygen is supplied to the solution such that discharge efficiency of thecharging and discharging apparatus for the coin-type secondary batterycan be increased.

The oxygen supplier 230 may include a circulation pipe 233 connected tothe vessel 110 in which the solution is accommodated, and configured todischarge the solution; a pump 232 connected to the circulation pipe 233and configured to circulate the solution; and a discharge pipe 234connected to an outlet side of the pump 232, extending above the vessel,and configured to discharge the solution discharged through the pump 232over a surface of the solution of the vessel 110.

A housing 231 for installing the pump 232 is coupled to an outer side ofthe vessel. The pump 232 and a configuration for driving the pump 232 oradjusting a flow rate thereof may be provided inside the housing 231. Inaddition, in order to manipulate the pump 232, an on-off switch of thepump 232 or a switch 235 configured to adjust a flow rate of the pump232 may be installed at an outer side of the housing 231.

An inlet side of the pump 232 is directly connected to the interior ofthe vessel through the circulation pipe 233. For example, thecirculation pipe 233 may be installed to pass through a lower sidesurface of the vessel 110 to be connected to the inlet side of the pump232. Accordingly, the solution accommodated in the vessel 110 flows intothe pump 232 through the circulation pipe 233.

The outlet side of the pump 232 is connected to an upper portion of thevessel via the discharge pipe 234. A distal end of the discharge pipe234 extending to the upper portion of the vessel 110 is disposed andspaced apart from the surface of the solution not to be in directcontact with the solution accommodated in the vessel. Thus, the solutiontransferred to the discharge pipe 234 according to the driving of thepump 232 is discharged from the distal end of the discharge pipe 234 todrop onto the surface of the solution.

During the above-described procedure, air bubbles flow into the solutionaccommodated in the vessel along with the solution dropping from thedischarge pipe 234 such that oxygen in the air is supplied to thesolution. The solution is continuously circulated according to thedriving of the pump 232, and air is supplied to the solution such thatoxygen in the air is continuously supplied to the solution.

As described above, oxygen is continuously supplied to the solution suchthat discharge efficiency can be further increased.

That is, since oxygen (O₂) is required for a discharge due to adischarging mechanism of the coin-type secondary battery, the solutionis circulated as described above to continuously supply oxygen in theair to the solution according to the apparatus of the present inventionsuch that discharge reaction efficiency can be maximized.

Further, the solution is circulated to continuously drop over thesolution of the vessel such that the apparatus of the present embodimentcan closely simulate an actual seawater situation in which waves arerippling. Therefore, a charge and discharge test for a coin-typesecondary battery can be easily performed under conditions similar toactual seawater conditions.

Hereinafter, charging and discharging procedures of a coin-typesecondary battery through the charging and discharging apparatusaccording to the present embodiment will be described.

Charging and discharging of the coin-type secondary battery 200 may beeasily performed through the charging and discharging apparatus 100 ofthe present embodiment.

Since the jig part 120 on which the secondary battery 200 is mounted isseparated from the vessel 110 in which a solution is accommodated, thejig part 120 can be separated from the vessel 110 to allow the secondarybattery 200 to be easily mounted thereon.

To mount the secondary battery 200 on the jig part 120, the sealingmember 140 is first installed at the coin-type secondary battery 200.Since the sealing member 140 is configured in a ring form, the sealingmember 140 is coupled to surround the outer circumferential surface ofthe coin-type secondary battery 200. The cathode part 210 and the anodepart 220 of the secondary battery 200 are each exposed through both ofthe open surfaces of the sealing member 140.

The sealing member 140 coupled to the secondary battery 200 is seated onthe seating recess of the case 130. Since the electrode plate 162 incontact with the anode part 220 of the secondary battery 200, which isfitted in the electrode plate 162, is mounted on the seating recess ofthe case 130, the anode part 220 of the secondary battery 200 is coupledto the electrode plate 162 and is disposed inside the case 130.

In this state, the carbon felt 172 is disposed at the cathode part 210of the secondary battery 200, and the cover member 150 is coupled to thecase 130. When the cover member 150 is completely coupled to the case130, the sealing member 140 is pressurized by the cover member 150 suchthat the cover member 150, the secondary battery 200, and the case 130are brought into close contact with each other by the sealing member140, thereby sealing between the anode part 220 of the secondary battery200 and the case 130. Consequently, when the solution inside the vessel110 flows into the jig part 120, the solution is blocked by the sealingmember 140 not to move to the anode part 220 of the secondary battery200.

Here, when the cover member 150 is coupled to the case 130 in a state inwhich the cathode rod 170 at which the coil spring 174 is formed ismounted on the cover member 150, the coil spring 174 pressurizes thecarbon felt 172 such that the carbon felt 172 is brought into closecontact with the cathode part 210 of the secondary battery.

In this state, when the anode rod 160 mounted on the case 130 is rotatedand tightened in one direction, the anode rod 160 enters into theinterior of the case 130 to push the electrode plate 162. Consequently,the electrode plate 162 pressurizes the secondary battery 200 such thatcurrent collecting efficiency by the electrode plate 162 and the carbonfelt 172 can be maximized. Further, as the electrode plate 162pressurizes the secondary battery 200, an adhering force of the sealingmember 140 is increased such that a sealing effect of the anode part 220against the solution can be further enhanced.

When assembly of the jig part 120 is completed, the jig part 120 isbonded to the vessel 110. When the jig part 120 is screw-coupled to thefemale screw thread formed on the hole of the vessel 110, the covermember 150 of the jig part 120 is disposed inside the vessel 110. Inthis state, the solution is supplied to the vessel 110. Thus, thesolution flows into the jig part 120 through the hole 152 formed at thecover member 150 to come into contact with the cathode part 210 of thesecondary battery 200 installed at the jig part 120. The anode part 220of the secondary battery 200 is disposed at a side opposite the cathodepart 210, and is sealed by the sealing member 140 so as not to bebrought into contact with the solution.

In the case of charging the secondary battery, a solution containingsodium, e.g., seawater, is supplied to the vessel 110. Further, acurrent is applied to the anode rod 160 and the cathode rod 170, whichare mounted on the jig part 120, so that the coin-type secondary battery200 may be charged.

When the current is applied to the anode rod 160 and the cathode rod170, sodium ions contained in the solution move to the cathode part 210of the secondary battery 200 through the carbon felt 172. Thus, chargingof the coin-type secondary battery 200 is performed.

In the case of discharging the secondary battery, seawater may be usedas the solution or water can be separately supplied into the vessel 110.When a load is applied to the anode rod 160 and the cathode rod 170,which are mounted on the jig part 120, in a state in which the solutionsuch as seawater or the like is filled in the vessel 110, sodium ionsmove from the cathode part 210 of the secondary battery 200 to thesolution in contact with the cathode part 210 such that discharge isperformed.

In the discharge procedure, the seawater in the vessel 110 is circulatedby the pump 232 being driven to supply oxygen to the solution ifnecessary, and thus discharge efficiency can be further increased.

As described above, the coin-type secondary battery 200 may be easilycharged or discharged using the solution such as seawater and the likethrough the charging and discharging apparatus 100 of the presentembodiment.

Those skilled in the art should understand that the present invention isnot limited to the above-described embodiments and may be implemented invarious forms, and other embodiments may be realized without departingfrom the technical spirit and essential features of the presentinvention. Therefore, it should be understood that the above-describedembodiments are not restrictive but illustrative in all aspects.

The invention claimed is:
 1. A method for manufacturing a coin-typesecondary battery, comprising: bonding one or more solid electrolytes toan anode upper case; forming an anode active material layer on an anodecurrent collector; sequentially stacking the anode current collector onwhich the anode active material layer is formed and the anode upper caseto which the one or more solid electrolytes are bonded on an anodebottom case to obtain an anode part; injecting a liquid electrolyte intothe anode part; disposing a gasket that has a direct contact with aninner side surface of the anode bottom case, an outer side surface ofthe anode upper case, and the liquid electrolyte, and prevents leakageof the liquid electrolyte injected into the anode part; sequentiallystacking the anode part, a separator, a cathode current collector, and asecond case including one or more openings on a first case; bonding thefirst case to the second case; and introducing an ion-containingsolution containing sodium, lithium, magnesium, and a combinationthereof from the outside of the second case into an interior thereof,wherein, in the bonding of the one or more solid electrolytes to theanode upper case, one or more openings are disposed in the anode uppercase and the one or more solid electrolytes are bonded to the one ormore openings in the anode upper case; and, in the introducing of theion-containing solution containing sodium, lithium, magnesium, and acombination thereof from the outside of the second case into a cathodepart, the ion-containing solution flows from the outside of the secondcase into the cathode part through the one or more openings of thesecond case, and wherein the separator is a non-electric conductivediaphragm, and prevents a short circuit between the anode part and thecathode part, wherein the cathode current collector comprises at leastone selected from the group consisting of a carbon paper, a carbonfiber, a carbon cloth, carbon felt, and a metal thin film.
 2. The methodof claim 1, wherein the bonding of the one or more solid electrolytes tothe anode upper case includes bonding the one or more solid electrolytesto the anode upper case using an adhesive.
 3. The method of claim 2,wherein the adhesive includes one or more materials selected from thegroup consisting of a silicon (Si) based material, an epoxy-basedmaterial, and a combination thereof.
 4. The method of claim 2, whereineach of the one or more solid electrolytes is selected from the groupconsisting of a Na superionic conductor (NASICON), a Li superionicconductor (LISICON), an amorphous ion conductive material, a ceramic ionconductive material, and a combination thereof.